


Nitrous

by LeoArcana



Category: Supernatural
Genre: Anal Sex, Bottom Dean, Dentistry, Dentists, Drugged Dean, Drugged Sex, Laughter During Sex, M/M, Nitrous Oxide, Top Castiel, improper use of dental equipment and supplies
Language: English
Status: Completed
Published: 2015-05-22
Updated: 2015-05-22
Packaged: 2018-03-31 16:54:02
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,467
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3985684
Author URL: https://archiveofourown.org/users/LeoArcana/pseuds/LeoArcana
Summary: <blockquote class="userstuff">
              <p>Dean had gotten the idea a week ago when Castiel had come home complaining about the number of patients needing nitrous, saying he felt like he’d gotten second-hand high.  He had his doubts and reservations about the idea, but Dean had managed to sell him on it.</p>
            </blockquote>





	Nitrous

**Author's Note:**

> based on [my post/thought i had at work earlier](http://leo-arcana.tumblr.com/post/119576155090/you-wanna-know-what-was-weird-today-at-work)

“The last patient is here.”

“Is the nitrous ready?”

“I was just about to go set it up.”

“Alright, as soon as it’s set up, you’re free to go for the day.”

“A-are you sure?  It says he’s got a few fillings to do and he has dental anxiety…”

“It’ll be alright.  They’re simple ones and the anxiety is what the nitrous is for,” Castiel replied simply.

The dental assistant lingered in the doorway, eyeing the dentist with suspicion.  He could practically see all the red flags popping up in her mind.  Castiel leaned back from his desk to look at her better, doing his best to give her the most reassuring look.

“I promise, I will be alright,” Castiel said, “I’ve met him outside of work before.  And if anything at all happens, I won’t let any of it come down on you.  You’re just doing what I said.”

The assistant chewed her lip for a moment, shifting her weight and studying Castiel’s face.  She had no doubt in her mind that he would keep any fallout away from her, but she wanted to know why.  He was making an effort to maintain his earnest expression and she could see it.  He swallowed reflexively under her gaze and knew the second she came to a realization.  She ducked her head for a moment and looked off to the side.

“Well, if you’re sure… Just, um, make sure the operatory is clean when you leave?” the assistant asked, “I, uh, don’t want to come in early to— _clean_ _everything_.”

“Of course.  I would never leave a mess after you’ve left.”

“I’ll just bring him back and then, uh…leave.”

Castiel went back to his computer to look at the last patient’s chart, watching her discreetly from the corner of his eye.  She pursed her lips, nodding stiffly and walking away.  When she was gone, he wondered if she’d been able to notice that this wasn’t even the right chart.  Probably, she was a observant and quick witted assistant.  Plus, it was the chart of the patient they’d just had not ten minutes ago.

He got up and went to the door of the office where he could hear the front room a little better.  He picked up on her voice calling the last patient, _Dean_.  There was the typical small talk as she walked him back, but she was being far more reserved than normal.  She definitely knew what was going on.  Castiel waited a few more seconds before going to the operatory.  He passed her in the hallway as she walked quickly to retrieve her things from the breakroom and leave; she was out the backdoor by the time he reached the operatory and the receptionist had left a half hour earlier.

Dean heard Castiel step into the room and twisted around to look up at him, flashing a grin.

“What’s up, Doc?”

“Nothing, just taking care of the last patient,” Castiel replied with a half-smile, “How are you?  Any pain?”

“Yeah, a little,” Dean shrugged.

“Where at?”

“Down south,” Dean winked.

Castiel dropped his head to hide a smile, rubbing at his nose a second before regaining composure and looking up again.

“What kind of pain is it?”

“Pretty constant throbbing,” Dean answered, “Been goin’ on since this morning.”

“That excit— long, hm?”

If anything, Castiel’s correction had Dean’s grin spreading wider with a mischievous glint in his eyes.  Castiel shook his head with a sigh; he couldn’t play this game.  He glanced down towards Dean’s hips and could see a noticeable bulge.  His assistant may know what was going on, but he still prayed to God Dean wasn’t sporting this when she walked him back.

“Are you sure you want to do this?” Castiel asked.          

“Hell yeah.”

“You do know a small percentage of people react adversely to nitrous, right?”

“How small?”

“Somewhere around one percent, last I checked.”

“Sounds like good odds to me, c’mon.”

“Alright.”

Castiel pressed a button on the side of the chair, making it automatically recline while he stood and walked over to the nitrous oxide tanks.  He picked up the small metal ‘key’ and twisted the tops of a blue tank and a green one, checking the dials on top of each.  Dean watched him closely as he twisted a nob on the front, sending two little metal balls up and bobbing in the measured glass.  He turned another, moving only a single ball, and checked another dial on a ribbed hose attached to the assistant’s cradle. 

Satisfied with the readings, he picked up the pair of white hoses that came together at an orange nose piece.  Dean squirmed on the chair in excitement as Castiel settled the nose piece over his face.  Castiel synched the hoses up behind the head rest, more or less securing Dean’s head.  Dean shivered and tried to will himself to stay still.

“You’re going to come in your pants before this even has a chance to take effect,” Castiel commented off-handedly.

“You should crank it up then,” Dean suggested.

“I’m not going to do that, it’s at a high enough rate,” Castiel replied flatly, “Breathe through your nose only, it’ll take effect faster.  You breathe through your mouth, it won’t do much of anything for you.”

Dean nodded and kept his mouth shut, taking deep breaths through his nose.  He closed his eyes, enjoying the fruity scent of the nose piece and gas, as Castiel stepped around the chair.  Castiel unbuckled Dean’s belt and undid his pants, tugging them down until the bunched up around his shins, hindered by his boots.  Dean haphazardly toed his boots off, allowing Castiel to remove the clothing.  Castiel pulled his boxers down with the flick of his wrists, freeing Dean’s hard and straining cock.  It sprang up to dab a drip of precome on his shirt.

“Like what y’see?” Dean taunted.

Castiel clamped his mouth shut, not even realizing it had fallen open.  His eyes darted up to Dean’s face and, from the lazy grin and relaxed expression, could see the nitrous was settling in.

“I always do.”

Soft giggles escaped Dean.  Castiel opened a drawer and grabbed the small bottle of Vaseline, reserved for patients with chapped lips.  As soon as he went to open it, Dean waved his hand in objection.

“Wait, wait, wait.  I got a better idea.”

“Better than this?” Castiel motioned to the entire room.              

Dean nodded quickly.

“Use that crappy tasting numbing stuff.”

“Topical anesthetic?  For lube?” Castiel asked incredulously.

“Yeah, that stuff.”

“Why?”

“Well, you could prep me a hell of lot faster,” Dean commented, “And it would taste better.”

“And my mouth would start to go numb,” Castiel added.

Dean made a noise of dismissal, half-heartedly waving both his hands.  But Castiel had to concede to Dean’s first point.  He tossed the Vaseline on the counter and grabbed the little bottle of strawberry pink anesthetic.  Being that he didn’t want to go numb, anywhere, he snapped a glove on his hand— Dean wriggled at the noise— and swiped a finger through the gel.  He crawled onto the chair, pausing as it groaned at the added weight, and balanced on his knees between Dean’s.  He used his free hand to grab the arm rest and steady himself while the other drifted past Dean’s cock without so much as a teasing touch.

He pressed his finger against Dean’s rim and flicked it back, leaving all the gel on the ring of muscle to sit for a moment.  Dean suppressed a shiver with a sharp breath through his mouth and a grin, only for Castiel to chide him on not breathing through his nose.  Dean licked lips and pursed them, resuming inhaling the gas. 

When Castiel pressed his finger to Dean’s hole again, a snicker escaped him.  Castiel eyed him for a second, a smirk playing at his lips.  Feeling brave between the nitrous and anesthetic, Castiel sank his finger in to the knuckle.  It stole Dean’s breath for a beat, but a stifled giggle bubbled up.  He worked his finger around quickly, then daring to push a second in just as roughly.  Aborted laughs spilled from Dean. 

Evidently, he was one of the few people who actually laughed while on the gas.  One of the even fewer who laughed harder the more something should hurt or cause discomfort.  Only once had Castiel had a patient like that, a little boy who laughed harder the more he drilled on his tooth.  His assistant had started laughing, in turn making him laugh as well.

Now wasn’t much different.  Castiel tried to bite down the laughter as he worked another finger into Dean, sending him into constant laughter.  Dean was stretched and prepped in record time, though honestly Castiel wouldn’t be opposed to more time just for the amusement.  But being they were still in his office, there was a part of his brain telling him they shouldn’t dawdle. 

He discarded his glove and sat back to undo his own pants.  He pushed down to just his thighs and went to shrug his lab coat off when Dean raised his hands and made a vain effort to sit up.  Castiel tilted his head to the side curiously.

“Le-leave it on, Doctor Sexy,” Dean winked.

Castiel snorted and dropped his head again.  So far, this was definitely the most entertaining sex they’d had in a long time.  Dean had gotten the idea a week ago when Castiel had come home complaining about the number of patients needing nitrous, saying he felt like he’d gotten second-hand high.  He had his doubts and reservations about the idea, but Dean had managed to sell him on it.  In a vain effort to cover up their plan, Castiel had made Dean sign in as a new patient a couple days ago and diagnosed him with needing several fillings.  He wasn’t wrong, Dean did need them, but they weren’t going to be done today.

Castiel straightened his jacket and returned to leaning over Dean; one hand braced on the arm rest, the other now stroking his own cock.  He settled back a little more to line himself up with Dean’s hole as he lifted his legs to wrap around Castiel.  Just before pressing in, Castiel remembered the anesthetic and pulled back slightly.  He thought about grabbing one of Dean’s discarded articles of clothing, but decided not to even bother.  It was well deep into him, he was going to get it on himself on way or the other.

Dean whined and dug a heel into his lower back, spurring him on.  Castiel took hold of his cock and lined up once again.  He pushed in, sliding smoothly up to the hilt and feeling thin stripes of anesthetic tracing the veins of his cock.  He shuddered at the feeling as breathy laughter rose out of Dean.  Castiel scowled at him and shifted his weight to lightly smack Dean’s chin, prompting him to shut his mouth.  Castiel didn’t want to inhale the escaping nitrous, weak as it may be at that point.

He pulled back, almost all the way out, and snapped his hips forward.  The chair trembled at the jarring movement, but Dean just laughed.  Castiel pulled back again and thrust forward with a little less force, but set an even and quick pace. 

Gradually, he picked up a little more force, testing just how hard he could thrust without pushing the chair too far.  Dean was beyond happy with whatever pace his set, head tipped back and smile permanently plastered on his face as he laughed and giggled.  Castiel couldn’t help but smile and snicker at the sight beneath him, dipping his head to kiss and nip at Dean’s jaw and neck, where the nitrous hoses allowed.

Dean’s cock bounced with each snap of Castiel’s hips, leaking precome profusely and wetting Dean’s shirt.  Castiel reached down, curling his fingers around Dean’s cock and pumped it in tandem with his thrusts.  Dean broke into full hearted laughter, tightening his legs around Castiel’s waist and wrapping his arms around Castiel’s neck to bring him closer.  Castiel peaked up, trying to see past the nose piece and caught a glimpse of a stray tear falling down Dean’s face.  Castiel snorted and buried his face into Dean’s shoulder as he started laughing almost as hard.

Castiel quickened his pace, pushing the chair to the limit, and chasing the orgasm building in his lower stomach.  Dean gasped for breath, each nitrous scented exhale coming in little _oh oh oh_ ’s that grew higher in pitch, as Castiel struck his prostate repeatedly, until his body shuddered and seized. 

Cum spilled over Castiel’s hand and on his shirt, landing as far up as his chest.  Dean clenched around Castiel as he continued pounding into him until his movements faltered and he seized with his own orgasm, coming deep inside Dean’s ass.  Castiel kept himself buried in Dean’s ass as he relaxed, glancing up at Dean.  Dean had gone almost completely limp under him, reduced to the occasional breathy giggles as he continued to milk Castiel’s cock for all it was worth.  Another wave washed over Castiel and spilled another load into Dean.

Castiel dropped to his elbows, catching his breath for a moment before blindly reaching for the nitrous tanks.  He couldn’t reach the key to shut off the tanks, but he could reach the nobs to stop the flow of nitrous and put Dean on just oxygen to flush his system.

There was a moment of renewed laughter just before his giggles weakened to amused hums, another minute or two before he was quiet completely.  Castiel tugged at the synch behind the headrest to loosen the nose piece and pushed it up off Dean’s face.  Dean scrunched his face up in annoyance at the unpleasant way of removing it, but the expression didn’t last long.

Dean lifted his trembling hands and cupped Castiel’s face, bringing him up for a kiss with as much love as he could muster; his body trembled every few seconds with the aftershocks.

“We’re taking these home,” Dean muttered.

Castiel shook his head and lifted himself up, not even wincing as his softening cock slipped from Dean’s fluttering hole.  Perhaps the anesthetic as lube wasn’t a bad idea.

“No, we are not,” Castiel stated.

“That’s what you said a week ago when I suggested this,” Dean winked.

Castiel opened his mouth to tell Dean that wouldn’t work.  Not only because he’d have no way to explain missing nitrous oxide tanks, but also because they didn’t have a compressor and vacuum system to use it.  But the logic died in his throat when Dean flashed him that look that had gotten Castiel to go along with the idea in the first place.

**Author's Note:**

> so yeah, i looked at chair today and got blindsided by the thought of Dean being fucked in a dental chair while on nitrous oxide. i was completely gone for the rest of the day and probably will be for all of tomorrow.  
> You can also make requests [on my tumblr](http://leo-arcana.tumblr.com/tagged/requests-and-prompts)


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